|By Amanda Becker and Richard Cowan

|By Amanda Becker and Richard Cowan

|By Amanda Becker and Richard Cowan

WASHINGTON (Reuters) - The three top Democrats in the U.S. House of Representatives called on Democratic congressman John Conyers on Thursday to resign in light of the sexual harassment allegations he faces, but Conyers' attorney said he was not thinking of stepping down.

House Democratic leader Nancy Pelosi said the allegations were "serious, disappointing and very credible" as she shifted away from comments four days ago in which she said Conyers, the longest-serving House member, was an "icon" who deserved due process.

"Zero tolerance means consequences for everyone," she told reporters on Thursday. "The brave women who came forward are owed justice ... Congressman Conyers should resign."

Pelosi's call was echoed by her second-in-command, Representative Steny Hoyer, and the No. 3 Democrat in the House, Representative James Clyburn. Like Conyers, Clyburn is known for his activism during the civil rights movement.

House Speaker Paul Ryan, the top House Republican, also said Conyers, who is 88 and has served since 1965, should step aside.

An attorney for the congressman said Conyers would not be hounded from office.

"It is not up to Nancy Pelosi," attorney Arnold Reed told reporters in Detroit, Michigan. "Nancy Pelosi did not elect the congressman, and she sure as hell won't be the one that tells the congressman to leave."

"That decision will be completely up to the congressman. He's not thought of that," Reed said.

Instead, Conyers was focusing on his health after being hospitalized late on Wednesday after suffering dizziness, light-headedness and shortness of breath, Reed said.

Conyers, who is facing an investigation by the House Ethics Committee, is one of numerous prominent men in U.S. politics, media and entertainment who have been accused in recent months of sexual harassment and misconduct. Others include former Hollywood executive Harvey Weinstein, Democratic Senator Al Franken and Republican Senate candidate Roy Moore.

Conyers has acknowledged settling with one former staffer over her claims of harassment, but he has denied wrongdoing. He has relinquished his post as the senior Democrat on the House Judiciary Committee and has said he will cooperate with the ethics probe.

The resignation calls came after one of Conyers' accusers, Marion Brown, detailed her allegations in a television interview on Thursday morning. Brown told NBC's "Today" show that the congressman had "violated my body" and frequently propositioned her for sex.

"No one should have to go through something like that, let alone here in Congress, so yes I think he should resign. He should resign immediately," said Ryan.

Reuters has not verified the allegations.

Republican and Democratic House members introduced a bill on Wednesday that would bar public funds from being used to settle sexual harassment claims against members and require previously made payments to be made public.

U.S. media have reported that Conyers used public funds to settle a claim with one of the women who had worked in his office.